Electric switch



Afl-HORST Lgz ELECTRIC SWITCH A Filed May 8, 1930 F2912. V i

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19 s Q13 w 2f E. .lf z 9b l zo' Mvg/vra@ QM m/ Patented Aug. 2 2, 1933UNITED STATES PAT-ENT ,OFFICE 8 Claims.

In switches with overload cut out arrangements there has ybeen atendency to substitute separate electromagnetic and thermal releasedevices for the combined electromagnetic-thermalv movable both by thearmature and independreleases formerly more usual. By combinedelectromagnetic-thermal release is meant a release device in which therelease armature of the overload magnet effects release notonly whenshort circuits or like overloads occur but also in the case ofrelatively small but protracted overloads, but is hindered from movingby a thermal relay as long as the relatively low overload has notexceeded an unpermissible period. In separate electromagnetic andthermal releases the armature of the overload magnet remains still aslong as short circuit or like overload currents do not occur. It onlymoves on the occurrence of such overloads. With relatively low butunpermissibly protracted overloads, the release action is effectedsolely by a thermal release.

The present invention relates to an overload switch with two magnetwindings for actuating the release armature, between which the movingswitch contact, and the switch locking and actuating mechanism with theoperating handle are located. Such switches are characterized by a verycompact construction, so that they are suitable for replacing the stillvery usual cartridge fuses. Owing to the shielding of the actuating andlocking mechanism on both-sides due to the magnet windings, it has notbeen possible hitherto lto provide such a switch 'with separateelectromagnetic and thermal releases. The actuating vand lockingmechanism is lonly free at its' lower end for the action of thearmature. Accordingly al combined .electromagneticthermal release devicehas been used. f Beneath the armature a current traversed and thereforecurrent heated bimetallic strip has been provided, to one end of whicha-helical spring was attached, of which the other end is attached to`the armature. Upon a short circuit occurring, with this arrangement thearmature is attracted in spite of the spring tension so that the lockingmechanism is released. If arelatively small overload current flows, thebimetallic strip slowly bends upwards so that after a certain time thespring is slackened to such an extent that the weak magnetic forcedeveloped by the overload sufces to attract the armature which releasesthe locking ,mechanism by its movement.

The present invention solves the problem ofV providing a switch of thiskind with an electro'- toggle.

(Cl. ZOO-88) magnetic and thermal release in such a manner that bothreleases act entirely independently. According to the invention amovable member is provided over the release armature which is entlythereof, and which passes through the plane of the armature and hasanabutment which is movable by a thermal release below the armature.

The accompanying drawingl illustrates an ex` 55 ample of the invention.Y

Figure 1 is an elevation in which the operating handle has been omittedto render the parts more visible.

Figure 2 is a longitudinal section, and

Figure 3 is a cross section.

On Athe base 1 of insulating material are secured two iron plates 2a and2b both bent up at right angles at the bottom, on which are carried thetwo magnet windings 3a and 3b serving 75 to actuate the releasearmature. Between the -plates 2a and 2b is the stationary switch contact4. The moving switch contact 5 is secured to a blade spring 6, theopposite end of which is gripped between clamping members '7 and 8; 'Ihe80 4 spring 6 tends to move the contact 5 away from the contact 4. Thefield between the plates 2a and 2b serves to blow out the arc formedwhen the switch is opened.

Between the two coils 3a and 3b on the plates 85 2a and 2b is theactuating and locking mecha-v nism and the operating handle. Theactuating Kand locking mechanism is formed by a double Its first linklies between the pivots 9 and 10, its second link between the pivots 10and 90 11, its`third link between pivots 11 and 12, and its fourth linkbetween pivots 12 and 13. The link 10, 11 has a projection 11a coactingwith the link 11, 12 so that these two links can only bend downwardlyjust beyond the dead centre position. The link between the pivots 12 and13 is vformed by the operatinghandle 14. The link 9, 10 is coupled forcommonmovemen't with the spring 6 and moving contact 5 so that when thislink turns about the vpivot 9 these two parts move 100 with it. The link11, 12 is provided with a horn 'Ihe plate form armature .16 on whichlies a similarly shaped plate 17 of insulating material, is secured to ablade .spring 18 which isv gripped 105 between the clamping members 7and 8.l It isl pressed by the spring 18V against one limb ofthe rightangle member 8.` v

-l v Above the armature lisa member 19 rotatable on the pivot-9. Thecentral part 19a ofthe mem- 110 ber 19 is bent upwardly, this partcooperating with the horn 15.

.23 is secured to the abutment 19h of the member 19 by lapped over ears23a. The member 19 rests with the spring 23 on the bimetallic strip 20.

The connections within the switch are arranged as usual. 'Ihe switch isconnected in circuit by the terminals 24 and 25.

In the position of the parts shown in Figure 2, the contacts 4 and 5 areapart and the circuit through the switch open. When the handle 14 ismoved upwards about the pivot 13, the toggle links 10, 1l and l1,12vremain unchanged in their positions relative to one another. The link9, l0 swings about the pivot 9 and with it the spring 6 until thecontact 5 bears on the contact 4 thus closing the circuit through theswitch. During the closing movement the horn 15 moves over the part 19aof the release'member 19.

Upon a short circuit occurring, or similar overload, the armature 16 issuddenly lifted by the action of the magnet windings 3a and 3b. In itsupward movement it lifts the member 19 which swings about the pivot 9.The mid part 19a over which the horn 15 is situated `causes the toggleformed by the links 1Q, 11 and 11, 12 to collapse upwards. Accordinglythe links 9, 10 can swing around the pivot 9 under the action of thespring 6 and the contact 5 leaves the contact 4. Clearly, this actionwill take place even if the handle 14 is held by hand in the on positionduring a short circuit. The switch therefore is of thetrip-free-from-therelease handle type. When the toggle 10, 11, 12 hasbeen' caused to collapse by the member 19 through the horn 15, thehandle 14 falls owing to its weight into the oi position, so that theposition of handle immediately `indicates whether the circuit throughthe switch is'open or closed.

With the switch on, the bimetallic strip 20 is traversed by current andtherefore heated. Owing to its rise in temperature it bends upwardsomewhat and presses the weak spring 23 slightly upwards. Owing to theweakness of the spring 23 however at rst no movement of the member 19occurs, the spring merely being slightly loaded. If an overload ofunpermissible amount occurs, the bimetallic strip 20 bends furtherupwards and if this current continues .the spring 23 is finally pressedagainst the abutment 19h and the insulator 21 on the strip 20 swings themember 19 upwards about the pivot 9. Accordingly the horn 15 locatedover the part'19a of member 19 is moved upwards so that the toggle 10,11, 12 is caused to collapse upwardly andthe cut out spring 6 comes intoaction. Releasing therefore takes place with relatively small butprotracted overloads by purely thermal action; the short circuit orrapid release armature 16 remains entirely at rest.

What I claim is:-

1. In an electric switch having an overload release device thecombination of a plate form release armature, a pair of magnet coilsarranged side by side above said armature for actuating said armature onthe occurrence of short circuits and like overloads, a moving contactmember, a switch actuating and locking mechanism and an operating handlemounted between said coils, an upwardly'moving plane bimetallic striptraversed by current mounted below and parallel to said armature, and arelease member pivoted above said armature in the path of movementthereof and passing through the plane thereof into the path of saidbimetallic strip, adapted to release said actuating and lockingmechanism. v

2. In an electric switch having an overload release device thecombination of a pair of magnet coils arranged side by side andenergized by the circuit controlled by the switch, a plate form releasearmature suspended on a spring beneath said coils in the field thereof,a double toggle between said coils, a moving contact member coupled toone end link of 'said double toggle, yspring means tending to move saidmoving contact member away from the stationary contact member, anoperating handle forming the other end link of said double toggle, anupwardly moving plane bimetallic strip heated by the currentin thecircuit controlled by the switch mounted beneath said armature parallelthereto, and a rotatable release member pivoted above said arm'- laturein the path thereof and having-a projection passing down through a cutout part of said armature into the path of said bimetallic strip,adapted to cause said toggle to collapse when lifted.

3. In an electric switch having an overload release device thecombination of a pair of magnet coils arranged side by side andenergized by the circuit controlled by the switch, a plate form releasearmature beneath said coils in the field thereof and attached to one endof a blade spring, a double toggle between said coils, any other bladespring carrying the moving contact and tending to move awayl from thestationary contact, coupled to one end link of said armature in the paththereof and having a projection passing down through a cut out part ofsaid armature into the path of said bimetallic strip, adapted to causesaid toggle to collapse when lifted.

4. In an electric switch having an overload release device thecombination of a pair of magnet coils arranged side by side andenergized by thecircuit controlled by the switch, a blade spring, g

a plate form release armature carried by said blade spring anddisposedbeneath said coils in thefield thereof, a double toggle betweensaid coils, a moving contact member coupled to one end link of saiddouble toggle, spring means tending to move said moving contact memberaway from the stationary contact, an operating handle forming the otherend link of said double toggle, an upwardly moving bimetallic stripheated by the current in the circuit controlled by the switch mountedbeneath zsaid armature parallel thereto,

a rotatable release member pivoted above said armature in the path ofmovement thereof and passing through the plane lthereof into the path ofsaid bimetallic strip, a horn on one link of said double toggleprojecting' into the path of movement of said release member and acurved part onv said release Amember cooperating with said horn. i

-ing switch contact and tending to move away from the stationary switchcontact coupled to one end link of said double toggle, an operatinghandle forming the other end link of said double toggle, an upwardlymoving plane bimetallic strip heated by the current in the circuitcontrolled by the switch mounted beneath said armature parallel thereto,a rotatable release member pivoted above said armature in the path ofmovement thereof and passing through the plane thereof into the path ofsaid bimetallic strip, a horn on one link of said toggle projecting intothe path of movement of said release member and a curved part on saidrelease member cooperating With said horn.

6. In an electric switch having an overload release device thecombination of a plate form release armature, a pair of magnet coilsarranged side by side above said armature for actuating said armature onthe occurrence of short circuits and like overloads, a blade springcarrying said armature, a moving contact member, a switch actuating andlocking mechanism and an operating handle mounted between said coils, anupwardly moving plane bimetallic strip traversed by'current mountedbelow said armature parallel thereto, a release member pivoted abovesaid armature in the path of movement thereof and passing through theplan'e thereof into the path of movement of said bimetallic stripadapted to release said actuating and locking mechanism, and a Weakspring secured to said release member Withit's free end resting on saidbimetallic strip.

net coils arranged side by side and energized bythe circuit controlledby the switch, a plate form release armature pivoted beneath said coilsin the field thereof, a double toggle betweensaid coils, a blade springcarrying the moving contact and tending to move away from thestationarycontact coupled to one end link of said double toggle, an'operating handle forming the other end link of said double toggle, aplane bimetallic strip traversed by the current in the circuit of theswitch mounted beneath said armature so that it bends upwardly when itstemperature rises, a rotatable release member pivoted above saidarmature in the path of movement thereof and having a projection passingdown .through a cut out part of said armature into the path of saidbimetallic strip, a weak spring secured to said release member with itsfree end resting on said bimetallic strip, a horn on the toggle linkpivoted to said handle projecting into the path of movement ofsaidrelease member, and a. curved part on the upper side of said releasemember cooperating with said horn.

8. In an electric switch with independently operating electro-magnet andthermal release, the combination of a rotatable release member convex onits upper side, a plate form armature 100 mounted upon a spring andlocated beneath said release member and having a cut loutportion throughwhich said release member passes downwardly, a plane bimetallic stripmounted beneath and parallel to said armature, said strip being 105heated by the `current and then bending upwardly so as to raise saidrelease member, a pair of coils arranged side by side above saidarmature and excited by the current and having their magnetic circuitpassing on the lower side 110 through said armature, cores in said coilsextending in plate form above said coils, a pair of respectively xed andmoving coacting contacts `between said plate form parts of said cores, adouble toggle between said coils adapted to actuate said movementcontact, and a horn on one of the mid members of said toggle cooperatingwith the said curved part of said release member.

ADAM HORST.

